<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>体验页面无刷新</title>
    <script>
        function go() {
            var url = document.getElementById('url').value;
            // 所有值的变量 提前获取
            document.getElementById('iframe1').src=url;
        }
    </script>
</head>
<body>
<div>
    <p>请输入地址：</p>
    <p>
    <input type="text" id="url">
        <input type="button" value="提交" onclick="go()">
    </p>
</div>
<div>
    <iframe id="iframe1" style="width: 100%;height: 500px"></iframe>
</div>
</body>
</html>